The big innovation of “American Idol,” when it premiered a decade ago, was the prominence of the judges panel. The three music arbiters — Simon Cowell, Randy Jackson, and Paula Abdul — were the driving forces behind the show’s success, as they sat sipping their conspicuous colas.

Yes, the rags-to-riches and karaoke-to-primetime story arcs of the young contestants were engaging. But viewers identified more with the judges than the singers in this new talent-show model, as we decided how to cast our votes. The appeal of the genre had shifted from aspirational (“I want to be a famous singer, too!”) to judgmental. The people on the bench — particularly Cowell, with his brutal honesty — were our surrogates. They were doing what we all do when we choose to buy or watch or listen in the overcrowded pop market — they were curating, to use the word du jour, making decisions about what’s worthy of time.

Related Link

Cut to: now. The judges are a garish joke, not just on “Idol,” but on most of the performance reality shows such as “The X Factor” that arrived in its wake. Cowell, Abdul, and Jackson — especially Abdul, whose stream-of-consciousness free verse was a thing of mad beauty — were certainly always a sideshow. But now most of the judges barely judge at all; they’re hired solely as a demographic incentive, to give the shows a fast, if temporary, ratings bump. They are freaky fashion plates and visual spectacles who, like Steven Tyler and Christina Aguilera, are HDTV migraines. The thing that gave the contemporary music contest its relevance is gone, leaving a trail of stale pop tarts such as Britney Spears and minor musical talents — Lee DeWyze, Kris Allen, Phillip Phillips — in its wake.

Advertisement - Continue Reading Below

The new faces of talent-show justice include, for “The X Factor,” Spears and Demi Lovato, and for “Idol,” Mariah Carey. All summer long, names have been thrown out as possible “Idol” judges, all of them gaudy, including Janet Jackson, Katy Perry, Kanye West, Adam Lambert, Nicki Minaj, and Alanis Morissette. This constant flow of rumors, reported by many news outlets, has become its own kind of promotional tour, both for the return of the shows (“The X Factor” next month, “Idol” in January) and for the potential judges. Each week, a new pop star is thisclose to signing on for THIS MANY millions. There have been more definite “Idol” judges this summer than definite “Live! With Kelly” cohosts, which is saying something.

To me, it is strange that judging reality shows has become a desirable — and not just a desperate — career move for icons like Tyler, Ellen DeGeneres, Christina Aguilera, and Howard Stern. Would West, maker of some of the most important music of the past decade, really want to sit watching wannabes manufacture pseudo-soul riffs night in and night out on camera? For me, Tyler and Jennifer Lopez both lost legitimacy as performers by their stints on “American Idol.” As they sat playing out their predictable little entr’actes with Jackson, they were only a half-step up on the dignity ladder from “celebreality” shows such as “Mrs. Eastwood & Company,” “The Surreal Life,” and “Married to Jonas.”

But of course I am so very wrong. What they may lose in legitimacy, they gain — and then some — in money, in sales, in buzz. They become part of the cultural conversation again, if only because, like Tyler, they make little sense and look like cartoons, or because, like Lopez, they are primping drama queens who photo bomb every camera shot of the judges panel. They may not need the money they will make from being a reality TV judge, but they need the weekly attention — whether it’s positive, negative, or ironic, it doesn’t matter.

For the likes of Spears, Lovato, Lopez, and Tyler, whose People magazine batteries may be running low on juice, serving as a reality judge has the potential to recharge. They and their agents see cover stories, red-carpet renewal, viral clips, and large Nielsen viewership numbers in their futures. Of course, the celebs don’t want to be the villains on the panels. Picking on kids? Scaring them straight out of delusion? That’s not good PR. Better to do what DeGeneres did for one excruciating season: Mutter fangless jokes and offend no one — except viewers looking for something even just a little forthright.

For years, Cowell was the breakout star of “American Idol,” as he anatomized pop stardom for mainstream viewers and empowered them to be honest in their taste. He was the sensation who lifted the show to record-breaking ratings, showing the world how music industry people assess talent. He reminded us that while candor may hurt, it’s best for all — including the crushed dreamer on the stage — over the long run.

Now, on “The X Factor,” he is out of gas, and hoping to squeeze as much ratings mileage out of Spears and Lovato as he can. Instead of finding a new Simon Cowell, he’s appealing to our addiction to watching train wrecks, dangling the possibility of Spears meltdowns before our eyes. “Idol,” meanwhile, is hoping that we’ll be drawn to Carey’s diva posing as well as her potential for crazy. The thought of Carey sharing the stage with Minaj – too juicy for words! Catfight! Catfight!

If someone told me Lindsay Lohan was on the short list of new “Idol” judges, I can’t say I’d be shocked. When the judges get arrested by the Fashion Police, anything is possible.

Matthew Gilbert can be reached at gilbert@globe.com. Follow him on Twitter @MatthewGilbert.